- Introduced language normalization utility functions to standardize language codes across the application.
- Updated ContractUploadController to resolve requested language from contract data and user settings.
- Enhanced authMiddleware to set preferred language in user object based on user settings.
- Added preferred_language column to user_settings table in the database.
- Implemented UserSettingsRepository to manage user settings, including preferred language updates.
- Updated DocumentTemplateService and AboContractService to support language-specific templates.
- Enhanced InvoiceService to select invoice templates based on normalized language codes.
- Added new script to compare versions of ABO contract documents.
- Refactored various services and repositories to utilize the new language normalization logic.
